Plastic Vapor Barrier For Concrete

Thin plastic like this is often called a vapor retarder meaning it slows the vapor down but doesn t stop it.

Plastic vapor barrier for concrete.

If you re in a cold climate and the subgrade soil is poorly drained a vapor barrier might be marginally useful. Always read the flooring manufacturers recommendations and instructions before installing the underlayment. Vapor barriers are a way to keep moisture from getting into the concrete. A vapor barrier against the concrete surface is generally recommended before wood framing or flooring materials are installed.

A much better approach is a true vapor barrier with characteristics that conform to the requirements of astm e 1745 standard specification for water vapor retarders used in contact with soil or granular fill under concrete slabs. For most commercial applications the 15 mil thick concrete vapor barrier will be a better choice. Very hot and humid climates may benefit from an exterior vapor barrier that keeps outside humidity from penetrating into walls. A concrete vapor barrier is simply a sheet of polyethylene plastic visqueen placed directly on top of the sub grade before the concrete floor or slab is poured to help keep moisture from the soil from passing up through the concrete.

It comes in a roll 14 feet by 140 feet. This is why a vapor barrier under concrete is essential. If you have a concrete floor that s in continuous contact with a source of moisture you re going to have problems. How to install vapor barrier on concrete floor under laminate flooring.

The american concrete institute s guide for concrete floor and slab construction recommends that the thickness of the vapor retarder be at least 10 mils. Puncture studies of 6 8 10 and 20 mil vapor retarder materials have shown that 10 mils is the minimum thickness that should be considered and thicker material may be necessary over. In temperate climates we see no advantage to placing a vapor retarder beneath a sidewalk. Barricade s 6 mil plastic sheeting is a general purpose plastic film for use in a variety of construction gardening and diy applications.

The concrete vapor barrier we use the most is stego wrap s 15 mil thick vapor barrier. Below grade walls and floor slabs transmit ground moisture through concrete walls or slabs. Before rolling out the underlayment be sure to sweep vacuum and remove all debris on the substructure. For sidewalks placed directly on the subgrade soil is a sheet plastic vapor retarder useful or harmful.